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JAMES MILLER, F NEW YORK., N. Y.

Letters Patent No. 61,629, :lated Jaitttvgry 29, 1867.

IMPROVED BORING troon EO ALL WHOM IT MAY' CONOERN:

Beit known that I, JAMES MILLER, of the city, county, and State of New York, have invented a certain new and useful Improvement in Expanding or Adjustable Tools for Annular Cutting or G-rooving applicable to cutting out tube heads in boiler-making and other purposes; and'l do hereby declare the following to be a Full, clear, and exact description of the same, reference being had to the accompanying drawing, which forms part of this specification, and in which- Figure 1 is a longitudinal view or elevation of my improved annular cutter, as adapted to be attached to and operated by a drilling machine.

Figure 2 is a vertical section of the same, taken as denoted by the lines :z: x in iigs. 3 and 4.

Figure 3 is an inverted plan-of the tool; and

Figure 4 a horizontal section taken through the line s z, figs. 1 and 2.

Like letters refer to'like parts in all the figures.

My-invention relates to a tool that may be driven by an ordinary drilling machine, in which cutters are employed on opposite sides of the centre of a revolving head, either for cutting out round holes in a body or plate by annularly grooving its surface till the cutters are projectedv through the plate, or by not cutting through the plate, merely grooving its surface, said cutters being adjustable to regulate the pitch or diameter of the cut, and being kept up to their work by forcing down the tool thereon, or feeding the work to the latter that rests on the Iwork by an adjustable centre; and my improvement consists, firstly, in apcc-uliarconstruction and arrangement oi' the'cutters iu adjustable slides within the revolving head, by arranging the cutting edges or front faces of the two opposite cutters` in a plane or thereabouts intersecting the tool at its centre, and forming the outer sides of said cutters of a sweep not exceeding or thereabouts the sweep of the smallest circle they are designed to movein ,also the inner sides of said' cutters preferably being made {lat to give increased facility for grinding, while the construction of the outer sides and arrangement of the front faces admit of the same cutters being used in all circles within the range of their adjustment inthe head that carries them; and my improvement further consists iua combination oi' opposite adjustable cutters, substantially of the character herein described, with a self-adjusting raising and lowering centreor centrelpin tothe head that carries the lcutters; likewise in combination, with a self-adjusting centre or centre-p in, of Acutters on opposite sides thereof, made separately adjustable relatively to said centre in their revolving head.

To enable others skilled in contrivances of the character to which this my improvement relates, I will now proceed to describe it-with reference to the drawing.

A-,is the stem of the revolving cutter-head B. VThis stem is designed to t in the spindle or stock of an ordinary drilling machine, and is made hollow to receive within it a centre-pin, C, that is ma'de to press outwards by means of a spring, a, arranged within the stem and caused to bear on a collar of thepin, a slot, Z1, in the latter and cross-bar or stop, c, serving to admit of the requisite up-anddown play to the centrepin,'a.nd to' lock it when fully projected. The cutter-head Bmay be of any suitable diameter, and is fitted on opposite sides of the centre-pin, and nearly opposite to each other, with slides, D. These slides are provided with cutter apertures, d e, arranged one outside. o f the other on opposite sides of Va Vster'rnf, to either slide, to give different diameters of cut, irrespective of the adjustment of theslidc, which is held steady to its way, in the head B, by a plate, y, on the upper sid'e of the latter, and wedge, 7L, passing through the stem j' ofv the slide. Either slide is further providedl with an adjusting screw, 7c, gearing into a female thread in the side of the slide and separately operative, that is, the one screw without the other, to admit of each slide being independently worked more or less out parallel with radial lincsfror'n the centre-pin. The cutters S S are plain bars of steel of similar conguration to the apertures d e, in the slides through which they pass, and in which they areiheld by set-screws, m and 7L, of diierent length, the longer screws, m, serving to hold the cutters when they are arranged on the inner sides of the stems f, and the shortest screws, a, to secure them when on the outer sides of said stems. These cutters are shaped and arranged as follows: the thickest and cutting edges or front faces, o, of the two opposite cutters are in a plane that intersects the piu C, atits cent/re or thereabouts, thcirpinner faces or sides, r, straight, and their outer faces or sides, seonvex, and of the same sweep rer thereabouts' as the sweep'of the smallest circle they; are designed to move in. Th's may he the construction of the cutters throughout their length, and

at both ends, so that they may be reversed to cut from either endl From this description, thefollo'sizing remarks will suffice to explain the general operation of the tool: Supposing it be desired to cut olut tube heads in boiler' plates, a .purpose for Which'this tool is specially adapted, instead of drilling out the plates in the old slow and wasteful method o'iV employing, for' the purpose, .a revolving ring with cutters adjusted by packing pieces, or scroll cutter with a. self-adjusting centre-pin, Magnin, as has been proposed, a different construction. of..cutte1s, with the head that carries them worked by hand to unscrew. down over the ccntre-pin,'it is here only' necessary toadjust, by the 'screws k, the cutting edges orifaces o ofthe cutters S S to an equal and .requisite distancefrom the centre of the pin C, and .after centring said pin in the plate, to steady the plate by the one handivhile regulating the motion of the drilling-machine by the other, or using both hands to the plate, the cutter-head, in descending .over the .self-adjusting centre-pin, feeding the cutters up to their Work, till =tlie annular groove is made through the plate, which forms ythe'required hole,"

leaving a core to be afterwards utilized, If it be desired 'to cnt out Washers by the tool, then the slides being separately adjustable, the two cutters S S are set at different 'distances from the centre-pin, corresponding at their cutting edges to the inner and outer circumferences of the washer, and the 'same operation gone through as in cutting out tube heads. Having cutter apertures on either' side of thc stems f of the slides renders the adjustment of the slides by the screws m or n less .frequent and prolonged. By thciconstructionnnd arrange'- ment of the cutters S as-'de'scribcd, that is, by ther cutting edges or faces'o o f both being in aplane intersecting the pin C, at its centre', and giving their outer sidess a convex form not exceeding the smallest circle they are designed to move in, the same cutters areladapted to work in larger circles, as by such construction and arrangement the cuttingledgcs or faces'o will occupy the nearest and mostdistant points in the traverse of the cutter, or, in other words, no portiongof the bodies of the cutters the wake of the cutting edges will, 'on' varying the diameter of circle for them to travel in,r`be outside orinsicle of the course described Aby the outer and inner edges of the cutting faces o, which would not be the casein varying the diameter of the cut were the cutting edges or faces arranged considera-bly in advance,on opposite sides of a planeinters'cctngthe pin C at its centre, and their outer sides e, cfa sweep larger than the one circle the cutters were constructed to travel in, and which would require diiferent cutters for diierent diameters of grooves. This multiplicity of cutter-5,.

however, by the construction and arrangement I have described, is avoided, and the inner faces r of 'the cutters may be made flat, instead of a concave form, corresponding to the inner' sweep oflthegroove, by which construction the cutters may be more readily ground from time to timeiand made serviceable, and repaired when broken. The revolving head B I propose to provide iyictha lubricating cup, P, made adjustable or else arranged t`o t holes lying over the various diameters of grooves the cutters are intended to travel in, for oiling the work in the track of the cutters. Y A

What I here claim as new and useful, and desire to 'secure by Letters Patent,is

1. The combination, with adjustable slides D, in a cutter-head B, of cutters S S', on opposite sides of their centre of rotation, and with their two cutting edges o r faces o lying in a plane or thereabouts intersecting said centre, and their outer sides s of a sweep not exceeding, or thereabouts, the sweep of the smallest -circle they are designed to travel in, constructed and arranged substantially as specified.

2. The combination of the adjustable cutters S S', arranged substantially as described, with the self-adjusting centre or centre-pin C, and cutter-head B, essentially as herein set forth.

' JAMES MILLER.

Witnesses:

A. LE Online, I J. W. CooMss. 

